feat: Major fragmented mp4 optimisation

crates/camera-directshow/examples/cli.rs

@@ -114,10 +114,11 @@ mod windows {
                 .start_capturing(
                     &selected_format.media_type,
                     Box::new(|frame| {
-                        unsafe { dbg!(frame.sample.GetActualDataLength()) };
-                        // dbg!(frame.media_type.subtype_str());
-                        // dbg!(frame.reference_time);
-                        dbg!(frame.timestamp);
+                        let data_length = unsafe { frame.sample.GetActualDataLength() };
+                        println!(
+                            "Frame: data_length={data_length:?}, timestamp={:?}",
+                            frame.timestamp
+                        );
                     }),
                 )
                 .unwrap();

crates/camera-mediafoundation/examples/cli.rs

@@ -21,7 +21,7 @@ mod windows {
 
             let device_sources = DeviceSourcesIterator::new().unwrap();
 
-            if device_sources.len() == 0 {
+            if device_sources.is_empty() {
                 warn!("No devices found");
                 return;
             }

crates/camera-windows/examples/cli.rs

@@ -32,7 +32,8 @@ mod windows {
                 let Ok(bytes) = frame.bytes() else {
                     return;
                 };
-                dbg!(
+                println!(
+                    "Frame: len={}, pixel_format={:?}, timestamp={:?}, perf_counter={:?}",
                     bytes.len(),
                     frame.pixel_format,
                     frame.timestamp,

crates/enc-avfoundation/src/segmented.rs

@@ -3,7 +3,37 @@ use cap_media_info::{AudioInfo, VideoInfo};
 use cidre::arc;
 use ffmpeg::frame;
 use serde::Serialize;
-use std::{path::PathBuf, time::Duration};
+use std::{
+    io::Write,
+    path::{Path, PathBuf},
+    time::Duration,
+};
+
+fn atomic_write_json<T: Serialize>(path: &Path, data: &T) -> std::io::Result<()> {
+    let temp_path = path.with_extension("json.tmp");
+    let json = serde_json::to_string_pretty(data)
+        .map_err(|e| std::io::Error::new(std::io::ErrorKind::InvalidData, e))?;
+
+    let mut file = std::fs::File::create(&temp_path)?;
+    file.write_all(json.as_bytes())?;
+    file.sync_all()?;
+
+    std::fs::rename(&temp_path, path)?;
+
+    if let Some(parent) = path.parent()
+        && let Ok(dir) = std::fs::File::open(parent)
+    {
+        let _ = dir.sync_all();
+    }
+
+    Ok(())
+}
+
+fn sync_file(path: &Path) {
+    if let Ok(file) = std::fs::File::open(path) {
+        let _ = file.sync_all();
+    }
+}
 
 pub struct SegmentedMP4Encoder {
     base_path: PathBuf,
@@ -24,6 +54,7 @@ pub struct SegmentInfo {
     pub path: PathBuf,
     pub index: u32,
     pub duration: Duration,
+    pub file_size: Option<u64>,
 }
 
 #[derive(Serialize)]
@@ -32,10 +63,15 @@ struct FragmentEntry {
     index: u32,
     duration: f64,
     is_complete: bool,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    file_size: Option<u64>,
 }
 
+const MANIFEST_VERSION: u32 = 2;
+
 #[derive(Serialize)]
 struct Manifest {
+    version: u32,
     fragments: Vec<FragmentEntry>,
     #[serde(skip_serializing_if = "Option::is_none")]
     total_duration: Option<f64>,
@@ -55,7 +91,7 @@ impl SegmentedMP4Encoder {
         let segment_path = base_path.join("fragment_000.mp4");
         let encoder = MP4Encoder::init(segment_path, video_config, audio_config, output_height)?;
 
-        Ok(Self {
+        let instance = Self {
             base_path,
             video_config,
             audio_config,
@@ -65,7 +101,11 @@ impl SegmentedMP4Encoder {
             segment_duration,
             segment_start_time: None,
             completed_segments: Vec::new(),
-        })
+        };
+
+        instance.write_in_progress_manifest();
+
+        Ok(instance)
     }
 
     pub fn queue_video_frame(
@@ -106,15 +146,27 @@ impl SegmentedMP4Encoder {
     fn rotate_segment(&mut self, timestamp: Duration) -> Result<(), QueueFrameError> {
         let segment_start = self.segment_start_time.unwrap_or(Duration::ZERO);
         let segment_duration = timestamp.saturating_sub(segment_start);
+        let completed_segment_path = self.current_segment_path();
 
         if let Some(mut encoder) = self.current_encoder.take() {
-            let _ = encoder.finish(Some(timestamp));
+            if let Err(e) = encoder.finish(Some(timestamp)) {
+                tracing::warn!("Failed to finish encoder during rotation: {e}");
+            }
+
+            sync_file(&completed_segment_path);
+
+            let file_size = std::fs::metadata(&completed_segment_path)
+                .ok()
+                .map(|m| m.len());
 
             self.completed_segments.push(SegmentInfo {
-                path: self.current_segment_path(),
+                path: completed_segment_path,
                 index: self.current_index,
                 duration: segment_duration,
+                file_size,
             });
+
+            self.write_manifest();
         }
 
         self.current_index += 1;
@@ -131,7 +183,7 @@ impl SegmentedMP4Encoder {
             .map_err(|_| QueueFrameError::Failed)?,
         );
 
-        self.write_manifest();
+        self.write_in_progress_manifest();
 
         Ok(())
     }
@@ -143,6 +195,7 @@ impl SegmentedMP4Encoder {
 
     fn write_manifest(&self) {
         let manifest = Manifest {
+            version: MANIFEST_VERSION,
             fragments: self
                 .completed_segments
                 .iter()
@@ -156,17 +209,67 @@ impl SegmentedMP4Encoder {
                     index: s.index,
                     duration: s.duration.as_secs_f64(),
                     is_complete: true,
+                    file_size: s.file_size,
                 })
                 .collect(),
             total_duration: None,
             is_complete: false,
         };
 
         let manifest_path = self.base_path.join("manifest.json");
-        let _ = std::fs::write(
-            manifest_path,
-            serde_json::to_string_pretty(&manifest).unwrap_or_default(),
-        );
+        if let Err(e) = atomic_write_json(&manifest_path, &manifest) {
+            tracing::warn!(
+                "Failed to write manifest to {}: {e}",
+                manifest_path.display()
+            );
+        }
+    }
+
+    fn write_in_progress_manifest(&self) {
+        let mut fragments: Vec<FragmentEntry> = self
+            .completed_segments
+            .iter()
+            .map(|s| FragmentEntry {
+                path: s
+                    .path
+                    .file_name()
+                    .unwrap_or_default()
+                    .to_string_lossy()
+                    .into_owned(),
+                index: s.index,
+                duration: s.duration.as_secs_f64(),
+                is_complete: true,
+                file_size: s.file_size,
+            })
+            .collect();
+
+        fragments.push(FragmentEntry {
+            path: self
+                .current_segment_path()
+                .file_name()
+                .unwrap_or_default()
+                .to_string_lossy()
+                .into_owned(),
+            index: self.current_index,
+            duration: 0.0,
+            is_complete: false,
+            file_size: None,
+        });
+
+        let manifest = Manifest {
+            version: MANIFEST_VERSION,
+            fragments,
+            total_duration: None,
+            is_complete: false,
+        };
+
+        let manifest_path = self.base_path.join("manifest.json");
+        if let Err(e) = atomic_write_json(&manifest_path, &manifest) {
+            tracing::warn!(
+                "Failed to write in-progress manifest to {}: {e}",
+                manifest_path.display()
+            );
+        }
     }
 
     pub fn pause(&mut self) {
@@ -182,20 +285,25 @@ impl SegmentedMP4Encoder {
     }
 
     pub fn finish(&mut self, timestamp: Option<Duration>) -> Result<(), FinishError> {
-        if let Some(segment_start) = self.segment_start_time {
-            let final_duration = timestamp
-                .unwrap_or(segment_start)
-                .saturating_sub(segment_start);
-
-            self.completed_segments.push(SegmentInfo {
-                path: self.current_segment_path(),
-                index: self.current_index,
-                duration: final_duration,
-            });
-        }
+        let segment_path = self.current_segment_path();
+        let segment_start = self.segment_start_time;
 
         if let Some(mut encoder) = self.current_encoder.take() {
             encoder.finish(timestamp)?;
+
+            sync_file(&segment_path);
+
+            if let Some(start) = segment_start {
+                let final_duration = timestamp.unwrap_or(start).saturating_sub(start);
+                let file_size = std::fs::metadata(&segment_path).ok().map(|m| m.len());
+
+                self.completed_segments.push(SegmentInfo {
+                    path: segment_path,
+                    index: self.current_index,
+                    duration: final_duration,
+                    file_size,
+                });
+            }
         }
 
         self.finalize_manifest();
@@ -207,6 +315,7 @@ impl SegmentedMP4Encoder {
         let total_duration: Duration = self.completed_segments.iter().map(|s| s.duration).sum();
 
         let manifest = Manifest {
+            version: MANIFEST_VERSION,
             fragments: self
                 .completed_segments
                 .iter()
@@ -220,17 +329,20 @@ impl SegmentedMP4Encoder {
                     index: s.index,
                     duration: s.duration.as_secs_f64(),
                     is_complete: true,
+                    file_size: s.file_size,
                 })
                 .collect(),
             total_duration: Some(total_duration.as_secs_f64()),
             is_complete: true,
         };
 
         let manifest_path = self.base_path.join("manifest.json");
-        let _ = std::fs::write(
-            manifest_path,
-            serde_json::to_string_pretty(&manifest).unwrap_or_default(),
-        );
+        if let Err(e) = atomic_write_json(&manifest_path, &manifest) {
+            tracing::warn!(
+                "Failed to write final manifest to {}: {e}",
+                manifest_path.display()
+            );
+        }
     }
 
     pub fn completed_segments(&self) -> &[SegmentInfo] {